Hi Luke,

Wood ashes have a carbon/nitrogen ratio of about 25:1 and are a good addition to a compost pile. They are an good source of calcium and potassium but are also very alkaline. Use them sparingly to avoid high pH levels that will limit microbial activity in the pile. Avoid composting charcoal briquettes as they take far too long to break down. Also, do not compost the ashes from purchased "firelogs" which contain wax and other petroleum derivatives.

Hope this helps